Stream-lined strut



L. T. FREDERICK.

STREAM LINED STRUT. APPLICATION men 11min, 191s. 19493931@ Patented Jau. Mb, 1923,

Cri

@CULS T. FREDERICK,

Application filed .une l?, M18. Serial lo. 249,285.

To @ZZ whom it may concern:

lle it known that l", Leurs T. Fnnnnnien., a sen of the United States, and a resident of ,'illriushurg, in the county of Allegheny f l?"ennsylwania have invented a new and useful lhfiprovernenaJ in Stream" l 'ned Struts, of Twhich the following is a specification.

My invention relates to improvements in stream-lined struts, and it has for its primary object the construction of a strut of holle-iv rectangular section stream-lined with one cr more sections of properly shaped tubes comprising superimposer. laniinations of impregnated sheet material.

lleretofore, it has been customary, in making struts of Troon, to employ a single strip or rod of Wood and to apply a suitable stream-lining thereto, this necessitating care ful selection and sha ing of the Wood and oon-sequent employment of skilled labor. ln view of this, another object of my invention is to construct a stream-lined strut in which. eral strips of 1wood may he employed to the st ut and thus greatly decrease the ccssity oi employing' Wood as clear and ee of hleinis ies as that usually required. l 's therefore7 maires possible the use of ed which previously has been discarded 'nce any reduction in Weight, Without the rilice of strength of the structural eleents used in aeroplane construction, is

ntageous, another object of my invenis to construct a built-up strut of hollow tangular section which siall he of ess 'C' -t and have as great strength as ordinary struts of solid section.

le. further ohiect of my invention is to construct a strut Which Will loe less liable to he seriously damaged hy hullcts and small shell fragments.

i still further object of my invention is to construct a strut of hollow rectangular section adapted to he stream-lined with lengths of proper y shapet tubes and to join and support the tubes hy means of hloclrs disposed at suitable intervals along the strut.

lilith these 'and other objects in vie.v a het-ter understanding of my invention may he had by reference to the drawings in vwhich l is a transverse sectional view of a stream-lined strut embodying my invention; 2 is a side elevation7 partly in section,

of the strut shown in Fig'. i; il ig'. 3 is a side elevatioin on a smaller scalej of a strut oon*- structed in accordance with nly invention, parts being hrolren showing several support-ing blocks and the joined ends of the short lengths of the streamlining enclosing the strut.

ln practising my invention, l may fasten four strips of ,Wood7 or oth r suitable material, such as impregnated sheet material, together to forni a hollen7 rectangular strut. hhout tie trut, thus formed, a suitable stream-lining may he applied -which may have properly shaped supporting elements or hloclrs interiorly disposed at intervals along its length for the purpose of supporting the stream-lining or as a means for fastening the stream-lining to hold it in place when several lengths of it are used in completing the structure.

Referring to the drawings, the parallel. strips l are fastened, hy any suitable means,

4rroiv parallel strips 2 to form a holloiv rectangular strut. ln stream-lining the strut, either of the narrower strips 2 that are fastened to the edges of the Wider strips l may be considered as the front, and hloclrs 3 may he fastened thereto at intervals along the strut. Bloclrs l are fastened to the Wider parallel strips l and hloclrs 5 are fastened to the rear of the strut forming the trailing edge. The hloclrs 8a l and 5, thus positioned about the strut, are preferably and have substantially the same spac- The assembled hloclrs i alone' the strut. c ,niorm to tlie shape of the streamlining 6 which surrounds the strut and the loloclrs. he stream-lining 6, which encloses the strut yl1roughout entire length, may he in one piece or of short lengths which have their hu ting ends T fastened to the blocks 3, si

5 hy screivs 8, or other suitable means. ln order to he edicient, as a structural ele- Aent in aeroplanes, a strut should have its greatest cross-sectional strength in the anis of its direction of movement when the plane is in flight which is one reason for the design of tie ype of strut disclosed. The eniployment of rods and tubes of circular or rectano'ular cross section as struts involves "-i Waste of material because, in order to secure sufficient strength in one direction, a superfluous amount of material must he used in the other. Struts of elliptical cross section overcome this difficulty to a certain eX- tent but they require careful work in properly shaping them. Furthermore, a onepiece strut, if struck by a bullet or shell fragment, is more likely to be'vitally damaged than is a built-up strut of the type set forth. A strut constructed inv accordance with my invention Vtherefore overcomes all A of the difliculties described above and may end to end to enclose the strut throughout its entire length.

2. A hollow strut built up of longitudinal strips having supporting elements disposed at intervals thereon and stream-line tubes disposed end to end about the strut and secured to the supporting elements.

' 3. A strut of hollow, rectangular section having supporting elements disposed at intervals Vthereon and stream-line tubes disposed endk to end about the vstrut and se- Y cured to the Lsupporting' elements.

4. A strut of hollow, rectangular section having supporting elements disposed at intervals thereon and stream-line tubes dis-` posed end to end about the'strut and secured to the supporting elements, the inner faces of the .supporting elements closely engaging the outer surfaces of the Vstrut and the outer faces of the supporting elements coming in close Contact with the stream-line tubes. Y

In testimony whereof l have hereuntosubscribed my name this 31st day of May, 1918.

Louis fr. FREDERioK. 

